English
Related papers

Related papers: Oscillations in stellar superflares

200 papers

A peculiar microwave quasi-periodic pulsation with zigzag pattern (Z-QPP) is observed first by the Chinese Solar Broadband Spectrometer in Huairou (SBRS/Huairou) at 1.10-1.34 GHz in a solar flare on 2005-01-15. The Z-QPP occurred just in…

Solar and Stellar Astrophysics · Physics 2013-06-14 Baolin Tan

A phenomenological relationship between oscillations in a sunspot and quasi-periodic pulsations in flaring energy releases at an active region above the sunspot, is established. The analysis of the microwave emission recorded by the…

Solar and Stellar Astrophysics · Physics 2015-05-19 R. Sych , V. M. Nakariakov , M. Karlicky , S. Anfinogentov

Post-flare loops are loop-like plasmas observed during the decay phase of solar flares, and they are expected to exist for stellar flares. However, it is unclear how post-flare loops are observed in stellar flares' cases. To clarify…

Solar and Stellar Astrophysics · Physics 2024-09-13 Takato Otsu , Ayumi Asai , Kai Ikuta , Kazunari Shibata

In this review I present an overview of our current understanding of the physical mechanisms that are responsible for the excitation of pulsations in stars with surface convection zones. These are typically cooler stars such as the Delta…

Solar and Stellar Astrophysics · Physics 2012-01-04 G. Houdek

This paper studies the oscillatory stability of uniformly rotating main-sequence stars of mass 3-8 M_sun by solving the linearized non-adiabatic, non-radial oscillation equations with a forcing term and searching for resonant response to a…

Astrophysics · Physics 2009-11-11 G. J. Savonije

During the survey phase of the Kepler mission, several thousands of stars were observed in short cadence, allowing the detection of solar-like oscillations in more than 500 main-sequence and sub-giant stars. Later, the Kepler Science Office…

Solar and Stellar Astrophysics · Physics 2021-12-29 S. Mathur , R. A. García , S. N. Breton , A. R. G. Santos , B. Mosser , D. Huber , M. Sayeed , L. Bugnet , A. Chontos

The sunspot-associated sources at the frequency of 17 GHz give information on plasma parameters in the regions of magnetic field about B=2000 G at the level of the chromosphere-corona transition region. The observations of short period…

Solar and Stellar Astrophysics · Physics 2015-03-19 Vladimir E. Abramov-Maximov , George B. Gelfreikh , Kiyoto Shibasaki

Large-scale extreme-ultraviolet (EUV) waves commonly exhibit as single wavefront and are believed to be caused by coronal mass ejections (CMEs). Utilizing high spatiotemporal resolution imaging observations from the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2024-09-27 Xinping Zhou , Zehao Tang , Zhining Qu , Ke Yu , Chengrui Zhou , Yuqi Xiang , Ahmed Ahmed Ibrahim , Yuandeng Shen

Using data from observations made with XMM-Newton, we present an X-ray analysis of two flares observed in $\xi$ Boo. The flare loop parameters are derived using various loop models including state-of-the-art hydrodynamic flare model. The…

Solar and Stellar Astrophysics · Physics 2017-08-02 J. C. Pandey , A. K. Srivastava

The Kepler mission revealed a plethora of stellar variability in the light curves of many stars, some associated with magnetic activity or stellar oscillations. In this work, we analyse the periodic signal in 162 intermediate-mass stars,…

Soft gamma-ray repeaters (SGRs) are widely understood as slowly rotating isolated neutron stars. Their generally large spin-down rates, high magnetic fields, and strong outburst energies render them different from ordinary pulsars. In a few…

High Energy Astrophysical Phenomena · Physics 2023-11-07 Hong-Bo Li , Yacheng Kang , Zexin Hu , Lijing Shao , Cheng-Jun Xia , Ren-Xin Xu

The high frequency oscillations discovered in the tails of giant flares from two magnetars are thought to be the first direct detections of seismic vibrations from neutron stars. The possibility of starquakes associated with the giant…

Astrophysics · Physics 2008-11-26 Anna L. Watts , Tod E. Strohmayer

Magneto-elastic oscillations of neutron stars are believed to explain observed quasi-periodic oscillations (QPOs) in the decaying tail of the giant flares of highly magnetized neutron stars (magnetars). Strong efforts of the theoretical…

High Energy Astrophysical Phenomena · Physics 2018-01-10 Michael Gabler , Pablo Cerdá-Durán , Alexei Mate , Nikolaos Stergioulas , José A. Font , Ewald Müller

Sun-like stellar oscillations are excited by turbulent convection and have been discovered in some 500 main sequence and sub-giant stars and in more than 12,000 red giant stars. When such stars are near gravitational wave sources, low-order…

Solar and Stellar Astrophysics · Physics 2015-07-14 Ilídio Lopes , Joseph Silk

An investigation of the G-type stellar population with Kepler (as done by Maehara et al.) shows that less than 1 per cent of those stars show superflares. Due to the large pixel scale of Kepler ($\sim4 arcsec \: px^{-1}$), it is still not…

Solar and Stellar Astrophysics · Physics 2014-08-13 M. Kitze , R. Neuhäuser , V. Hambaryan , C. Ginski

We searched for superflares on solar-type stars using the Kepler short-cadence (1-min sampling) data in order to detect superflares with short duration. We found 187 superflares on 23 solar-type stars whose bolometric energy ranges from the…

Solar and Stellar Astrophysics · Physics 2017-01-11 Hiroyuki Maehara , Takuya Shibayama , Yuta Notsu , Shota Notsu , Satoshi Honda , Daisaku Nogami , Kazunari Shibata

Fast sausage modes (FSMs) in flare loops have long been invoked to account for rapid quasi-periodic pulsations (QPPs) with periods of order seconds in flare lightcurves. However, most theories of FSMs in solar coronal cylinders assume a…

Solar and Stellar Astrophysics · Physics 2021-11-17 Mingzhe Guo , Bo Li , Mijie Shi

Delta Scuti (delta Sct) stars are opacity-driven pulsators with masses of 1.5-2.5M$_{\odot}$, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy…

The habitability of planets is closely connected with the stellar activity, mainly the frequency of flares and the distribution of flare energy. Kepler and TESS find many flaring stars are detected via precise time-domain photometric data,…

Solar and Stellar Astrophysics · Physics 2023-01-19 Dong-Yang Gao , Hui-Gen Liu , Ming Yang , Ji-Lin Zhou

Convective envelopes in stars on the main sequence are usually connected only with stars of spectral types F5 or later. However, observations as well as theory indicate that the convective outer layers in earlier stars, despite being…

Solar and Stellar Astrophysics · Physics 2016-03-23 Victoria Antoci